The present invention relates to blood component testing generally, and more particularly to blood glucose level testing devices.
Heretofore, various methods have been developed to carry out a program of home glucose monitoring for diabetics. These methods typically require a piercing device for piercing the skin of the patient to obtain a capillary blood sample and a separate device or mechanism for testing the concentration of glucose in the sample. Typically, automatic lancets, which include a generally complex arrangement of elements that cooperate to automatically trigger and retract a needle (lance), are used to pierce the skin. During use, the tip of the automatic lancet is placed lightly against the chosen site on a finger of a patient. A trigger is actuated which causes the lance to penetrate the skin. Some of these lancets are constructed such that the lance immediately retracts inside the lancet after making the skin puncture. Then the automatic lancet is lifted away from the finger and put aside, while a large drop of blood is allowed to form at the puncture site. One way in which the blood sample is tested is with what is known as a test strip. These test strips generally include reagents which when placed in contact with the blood sample undergo a change in color that indicates the glucose level of the sample. One such test strip is made by Miles, Inc., Diagnostic Div., Elkhart, Ind. and marketed under the name Glucofilm.TM.. These strips are typically stored in a bottle to avoid contamination.
When removing a test strip from its bottle, the user must be careful not to use the hand which has been pierced with the lancet. Otherwise, the blood sample could be lost from the pierced finger. The strip is placed on a flat dry surface with the target area of the strip (i.e., the reagent area) facing upward. The punctured finger is then positioned such that the blood forms a hanging drop which will naturally spread over the target area on contact. A proper size drop forms a small dome that completely covers the target. It is also important that the user not smear the blood sample onto the test strip or cover the area of the test strip that surrounds the reagent with the blood sample. Otherwise, inaccurate blood glucose level readings can result.
One of the drawbacks of the procedure described above is that it is awkward. Once the lance has been actuated to puncture a chosen site on the finger, only one hand is available to put aside the automatic lancet, obtain a test strip and position that strip such that a blood sample can be properly deposited thereon.
In addition, the number of component elements used to carry out the method creates inventory problems. For example, the user must maintain a supply of lances for the automatic lancet and a supply of test strips. If the lancet or one of these supply items is unavailable, the patient's glucose level cannot be monitored. This can happen by inadvertently forgetting to pack the automatic lancet or an appropriate supply of lances or test strips when preparing for overnight or extended travel.
Therefore, there is a need to provide a system for testing blood glucose levels that permits the procedure to be easily and reliably carried out. The system also should simplify inventory requirements.